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Cambridge International Examinations Cambridge International General Certificate of Secondary Education BIOLOGY (US) 0438/33 May/June 2016 Paper 3 Theory (Core) MARK SCHEME Maximum Mark: 80 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the May/June 2016 series for most Cambridge IGCSE®, Cambridge International A and AS Level components and some Cambridge O Level components. ® IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 13 printed pages. © UCLES 2016 [Turn over Page 2 Mark Scheme Cambridge IGCSE – May/June 2016 Syllabus 0438 Abbreviations used in the Mark Scheme: • • • • • • • • • • • • ; / I R A AW AVP ecf ora () underline max separates marking points alternatives ignore reject accept (for answers correctly cued by the question, or guidance for examiners) alternative wording (where responses vary more than usual) any valid point credit a correct statement / calculation that follows a previous wrong response or reverse argument the word / phrase in brackets is not required, but sets the context actual word given must be used by candidate (grammatical variants excepted) indicates the maximum number of marks that can be given © Cambridge International Examinations 2016 Paper 33 Page 3 Question 1 (a) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Syllabus 0438 Marks jointed legs ; Guidance R 3 pairs jointed legs segmented (body) ; exoskeleton ; (b) (i) (ii) insects ; [max 1] [1] 6 legs / 3 pairs of legs ; 3 body parts ; has (1 pair of) antennae ; wings ; Paper 33 [max 2] [Total: 4] © Cambridge International Examinations 2016 Page 4 Question 2 (a) (i) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Syllabus 0438 Marks Guidance narrower lumen / AW ; thicker wall ; more muscular / elastic wall ; valve present (at base) / AW ; (ii) (b) [max 2] low pressure, oxygenated ; [1] vena cava pulmonary artery pulmonary vein aorta 3 or 4 correct = 3 2 correct = 2 1 correct = 1 ;;; [3] [Total: 6] 3 (a) (i) (ii) transpiration / evaporation ; [1] cortex cells xylem mesophyll cells stomata Paper 33 3 or 4 correct = 3 2 correct = 2 1 correct = 1 [3] ;;; © Cambridge International Examinations 2016 Page 5 Question (b) (i) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Marks description decrease / AW ; plateau ; data quotation / usage ; explanation plant absorbs water ; (lost by) transpiration / evaporation ; rate of transpiration / evaporation varies ; reason as to why it varies ; (ii) (425–380=) 45 (cm3) ; (iii) has bigger leaves ; [max 4] [1] more leaves ; larger surface area ; [max 1] [Total: 10] © Cambridge International Examinations 2016 Syllabus 0438 Paper 33 Guidance Page 6 Question 4 (a) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Syllabus 0438 Marks diet with all classes / groups of nutrients; Paper 33 Guidance A list of at least 5 groups. in the correct proportions ; in the correct amounts ; ref. to energy ; idea of staying healthy ; (b) (i) [max 2] (rich in) carbohydrates / starch ; provide energy / joules / calories; for physical activity / body processes ; (ii) must have at least 2 foods meat / fish / eggs / beans / milk and dairy foods ; needed for growth / repair / to make enzymes / build muscles ; (iii) [max 2] [2] obesity / overweight ; CHD / heart disease / high blood pressure ; diabetes ; liver disease / gall stones ; [max 1] © Cambridge International Examinations 2016 Page 7 Question (iv) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Syllabus 0438 Marks age of person ; if they are growing or not ; Paper 33 Guidance one mark for factor and one mark for explanation. explanation must be linked to the factor activity of person ; idea of more food (group) for energy / repair or build tissues ; obese / anorexic ; might need to lose or gain weight ; gender ; females generally require less than males ; A sex pregnancy or lactating ; more food need ; ref. to different metabolic rates ; needing more or less food ; medical conditions e.g. diabetes, allergies, illness ; need to avoid gluten / sugars / fats / allergens / lactose OR need to eat certain food to alleviate a medical condition ; personal choice / vegetarian / vegan / religious / taste ; appropriate change in diet to suit choice diet ; [max 4] [Total: 11] © Cambridge International Examinations 2016 Page 8 Question 5 (a) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Syllabus 0438 Marks Guidance change the genetic material (of an organism) ; by removing / changing / inserting (individual) genes ; from one organism / species to another ; (b) (i) (ii) [max 2] length of DNA ; that codes for a protein; [2] insecticide in leaves will kill insects ; (fewer insects) means less plants eaten ; (so) more leaves / plants allows more photosynthesis / growth; higher (crop) yield ; less / no money spent on insecticides ; (c) (i) (ii) pollen / male gamete, transferred (from anther) to stigma / female plant / gamete ; (d) [max 2] [1] fewer, insects / pollinators; apples are not pollinated ; [max 1] any 2 from: herbicide resistance / enhance crop nutritional value / increase drought tolerance / disease resistance / produce insulin / bioluminescence / AVP ;; Paper 33 R insecticide [max 2] [Total: 10] © Cambridge International Examinations 2016 Page 9 Mark Scheme Cambridge IGCSE – May/June 2016 Question 6 (a) Answer Marks chemical; produced / secreted by a (endocrine) gland; carried / transported in the blood / plasma ; to a target organ; [max 3] (b) (i) part J name hormone pancreas ; insulin adrenal glands ; adrenaline K Reproductive organs ovaries oestrogen / progesterone ; testes ; testosterone ; [5] © Cambridge International Examinations 2016 Syllabus 0438 Paper 33 Guidance Page 10 Question Mark Scheme Cambridge IGCSE – May/June 2016 Answer Syllabus 0438 Marks Paper 33 Guidance (ii) situation: in (named) fright, fight or flight’ situations ; importance: (body changes) allows for escape / avoidance / preparation for activity / to survive ; [max 2] [Total: 10] 7 (a) rapid reproduction ; can make complex molecules ; cheaper to produce ; (b) (i) [max 2] (contain ) enzymes; [2] break down / digests food molecules (in stain); (ii) at high temperature enzymes, do not function / inactive / destroyed ; A denatured R enzymes die / killed enzymes more active at 30°C ; A optimum temperature is 30°C AVP ; (iii) (c) [max 2] enzymes are catalysts / not used up in the reaction ; [1] lipase ; [1] e.g. 60oC uses more energy than 30°C [Total: 8] © Cambridge International Examinations 2016 Page 11 Question 8 (a) (i) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Marks (b) (i) (ii) Paper 33 Guidance line touching lens; labelled lens; (ii) Syllabus 0438 [2] line touching retina ; labelled retina ; [2] transmission of genetic information from generation to generation ; [1] recessive – only expressed when there is no dominant (allele of the gene) present ; allele – a version of a gene ; [2] (c) all correct = 3 marks person genotype 1 gg 2 Gg 3 Gg 4 Gg 5 gg person 2 correct =1 person 1 and 5 correct = 1 person 3 and 4 correct =1 ;;; [3] [Total: 10] © Cambridge International Examinations 2016 Page 12 Question 9 (a) (i) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Syllabus 0438 Marks (an animal that gets its) energy by eating plants ; [1] (ii) decomposers ; [1] (iii) nutrients are recycled / resources are recycled ; Guidance A detritivores water is recycled; no need to feed ducks / fish ; idea of nothing extra is needed to sustain system / limited use of resources from outside the system; waste from one organism is used by another organism ; idea of self-contained system / self-sustaining system ; (b) [max 3] (resource) produced as rapidly as it is removed ; from the environment ; so it does not run out ; Paper 33 [max 2] [Total: 7] © Cambridge International Examinations 2016 Page 13 Question 10 (a) Mark Scheme Cambridge IGCSE – May/June 2016 Answer Syllabus 0438 Marks cushions / protects (fetus) ; Guidance I reference to maintains temperature allows (fetus) to move ; supports (fetus) ; (b) [max 1] box 2 and 3: cervix dilates / amniotic sac bursts (either order) ;; 3 or 4 correct = 3 2 correct = 2 1 correct = 1 box 4: baby passes down vagina ; box 6: placenta delivered ; Paper 33 [max 3] [Total: 4] © Cambridge International Examinations 2016